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中国人民解放军空军在2017年经历了一个多事之秋。9月，中国空军和巴基斯坦空军在中国境内举行了第六次“雄鹰（Shaheen VI）”联合训练。而台湾防务当局称，截至10月份，中国空军在2017年共进行了16次环岛演习。值得注意的是，中国空军在2017年扩大了军事演习的幅度和范围，吸引了该地区其他国家的注意。在某种程度上，2017年中国举行的空军演习与2016年相比有所降低，包括与日本航空自卫队近距离接触的频度，但最后几个月依然见证了一些转变。

朝鲜和美国之间爆发的朝鲜核试验僵局无疑是2017年东北亚地区最重要的安全议题。继朝鲜进行了一系列史无前例的导弹试验后，一些专家重新评估了平壤政权发展核武器的时间表，同时美国与韩国和日本沿韩国海岸线首次举行了联合军演。目睹其东海防空识别区附近如此频繁地举行联合军演，加上“鹞鹰（Foal Eagle）”和“乙支自由卫士（Ulchi-Freedom Guardian）”等美韩年度联合军演，中国军队如坐针毡。

有鉴于此，中国空军将军事演习扩展至包括在朝鲜半岛搜集情报的侦查任务。12月初中国宣布举行的军演就有侦察机的参与，这些侦察机或许已经飞越了中韩两国防空识别区的重叠区域。作为对首尔和华盛顿的直接回应，这些军事演习的威慑作用很有限。在当前情况下，美韩日联合军演与中国空军演习间的对比只是更加凸显了这种地区军事力量不平衡的差距。中国空军在太平洋地区面临着两个巨大的劣势：作战性能的技术局限和缺乏一个强有力的地区盟友。

在技术层面，中国空军的确还有很长一段路要走。中国空军在演习中使用的轰炸机基本上由“轰6K”组成，而“轰6K”是以早已过时的上世纪50年代苏联机体为基础研制而成。美国则拥有三个由B-52H轰炸机组成的空军联队，虽然该机型的服役期也较长，但都部署在美国本土，远距离的太平洋作战任务由更加先进的B-1B轰炸机执行。中国的“轰6K”已经升级改造为可搭载六枚对地攻击巡航导弹，但该机型的有效负荷和制导设计限制了其从中国本土发动攻击和威胁太平洋远洋目标的能力。“轰6K”3500公里的预计航程令其在执行大部分轰炸任务时只能搭载舰载型CJ-20巡航导弹，这意味着“轰6K”可选择的攻击目标有限，且精确制导功能会受到影响。轰炸机的示警作用——以攻击性的空中行动对新情况作出反应——会随着重复使用而逐渐失去其威力。例如，出动B-1B轰炸机对每次朝鲜导弹试验作出回应，会令美军无法相应地增强应对朝鲜新威胁的能力。如果说美韩战机飞越朝鲜半岛起到的威慑作用有限，那么中国空军出动“轰6K”对海上军演作出回应也仅仅显示了中国的抗议无非就是不在乎多浪费一些航空燃油。

如果说有一个领域是中国空军必须改进的，那就是发动机技术。中国当前服役的战机几乎全部使用俄罗斯发动机或从俄罗斯原型衍生而来的中国发动机，这些发动机都表现欠佳。对于“轰6K”以后的机型，它们的速度与范围都令人失望。中国新生产的第五代战斗机“歼-20”在研发过程中配载了几款发动机，现在使用的则是涡扇-15发动机。虽然涡扇-15的功能接近于美国上世纪90年代生产的发动机，但其机动性上没有推力矢量，同时可靠性也欠佳。虽然中国空军在短期内取得了长足的进步，但与美军相比无疑仍存在巨大的差距。

而中国空军的作战孤立又加剧了其技术短板。连续六年的中巴“雄鹰”联合军演深化了中国空军和巴基斯坦空军的合作，但两国间的同盟关系主要覆盖内陆领土。让我们对比一下中巴空军合作与美韩日在该地区的军事合作。进入21世纪20年代，美韩日将启用洛克希德马丁公司生产的F-35闪电II战斗机和韩国生产的KF-X战斗机，这两种机型将令三国空军脱胎换骨。而“歼-20”的一项优势——远程击落行动缓慢的支援机——将被多用途的F-35战机所抵销。融合了指挥、控制、通讯、电脑、作战系统、情报、监控和侦查等多功能的F-35战机实际上就是一个取代那些易受攻击支援目标的联网平台。因此，美韩日三国F-35战机的联合作战能够发挥聚合效应，而这正是中国空军所欠缺的。

鉴于中国空军在东亚安全领域面临着诸多不足，习近平将发展中国空军列为一项优先议题。在10月份举行的中国共产党第十九次全国代表大会上，习近平在演讲中点名提到了空军和火箭军，称这两者的发展对于建设“世界一流军队”至关重要。而新一代“轰-20”隐形轰炸机是朝实现这一目标迈出的重要一步。“轰-20”将成为中国版的美国B-2轰炸机，弥补“轰6K”能力上的不足。“轰-20”将令中国事实上完成自己的三位一体核打击能力，而中国火箭军在常规打击能力上的进步本身就值得注目。美国战略与国际研究中心（CSIS）在2016年发布的一份报告中强调，短程和中程常规武器的发展和扩散对中国的威慑战略来说至关重要。中国火箭军于1966年作为第二炮兵部队的分支机构设立，旨在发展中国的核武器威慑能力。火箭军承担的任务现已演变为双重威慑——核武器和常规武器，而这一演变过程凸显了中国在应对地区安全问题上更加多元化的思路。

习近平的强军理念并非体现在硬件发展上，而是人员配备。新一届中共中央军事委员会副主席由原中国人民解放军空军司令员许其亮担任，而原中国人民解放军火箭军司令员魏凤和位列第三。虽然中国陆军依然在中央军委占据着主导地位，但航空部队已经开始崛起，而这一趋势很可能会随着航空实力的增强而得以强化。回顾2017年，当下的军事演习暴露出中国空军的局限性，凸显了中国亟需一个地区盟友的必要性。但同时，中国空军在过去一年中也取得了进步，而且这种趋势将在未来几年内得到延续。

(Xinhua)

The People's Liberation Army Air Force had an eventful year in 2017. September saw the sixth annual “Shaheen” exercises with Pakistani forces, and the Taiwanese defense ministry has reported sixteen PLAAF exercises in nearby airspace during the year ending in October. Notably, the PLAAF has expanded the range and scope of its exercises during 2017, drawing the attention of other regional actors. Chinese aerospace exercises are down from last year by some metrics, including the frequency of Japanese Air Self Defense Force scrambles, but the last few months have nevertheless been transformative.

Far and away the top Northeast Asia security story of 2017 was the standoff between North Korea and the United States. Following an unprecedented series of North Korean missile tests that led some experts to reevaluate the regime's development milestone timeline, American bombers conducted drills along the South Korean coast in coordination with Republic of Korea and Japanese fighters for the first time. Chinese forces are on edge with so many military operations taking place near the East China Sea air defense identification zone (ADIZ), in addition to annually conducted US-ROK exercises like Foal Eagle and Ulchi-Freedom Guardian.

Exercises conducted by the PLAAF have therefore expanded to encompass a reconnaissance role to collect intelligence on the Korean Peninsula. Reconnaissance aircraft took part in operations announced early in December, which may have overflown the area where the Chinese and South Korean ADIZs overlap. As a direct response to Seoul and Washington, these exercises offer limited utility in terms of deterrence. Under current circumstances, the contrast between US-ROK-Japan exercises and PLA operations has only served to highlight a regional mismatch. The PLAAF faces two glaring presence disadvantages over the Pacific: technological limitations to operational performance and a lack of a substantive regional alliance.

On the technology front, the PLAAF has quite a bit of catching up to do. Its bomber force, which has been deployed during exercises, is primarily made up of Xian H-6K aircraft based on an outdated Soviet airframe dating to the 1950s. The United States maintains three wings of B-52H bombers, similarly long in the tooth, but based on the American mainland; long-range Pacific duties fall to the more advanced B-1B. The H-6K has been thoroughly updated to carry six sophisticated land attack cruise missiles, but payload and guidance specifications hinder its ability to project power from the Chinese mainland and threaten targets deep into the Pacific. Its estimated combat range of 3500 kilometers limits the H-6K to the CJ-20 cruise missile in attacking most targets; that means fewer targets can be selected, and precision may suffer. The practice of bomber signaling – response to new developments with aggressive airborne exercises – loses its bite with repetition. For example, answering each North Korean missile test with a B-1B flight provides no escalated response to new North Korean threats. If US-ROK flights over the Korean Peninsula are of questionable utility, the PLAAF's reactionary maritime exercises with the H-6K demonstrate little more than a willingness to burn jet fuel in protest.

If there is a single domain in which the PLAAF needs to see improvement, it must be engine technology. Current operational aircraft almost invariably use Russian engines or Chinese derivative models with relatively poor performance. For models beyond the H-6K, that means disappointing speed and range. China's newly-minted fifth-generation fighter, the Chengdu J-20, has been mated to a variety of engines during its development and now uses the Xian WS-15. While the WS-15 comes close to matching the performance of American engines of the 1990s, it lacks thrust vectoring for maneuverability and has been dogged by reliability issues. Great strides have been made in a short time, but a gap undoubtedly remains.

Technological hurdles are compounded by China's operational isolation. The six years of Shaheen exercises have deepened cooperation between the PLAAF and the Pakistani Air Force, but the alliance covers primarily inland territory. Compare the PLAAF-PAF partnership to the array of American, ROK, and Japanese forces operating in the region. Entering the 2020s, those three nations' collective airborne presence will be transformed by the introduction of the Lockheed Martin F-35 Lightning II fighter and the ROK KF-X fighter. One of the J-20's likely strengths – knocking out slow support aircraft from long range – is stymied by the F-35's multirole capabilities. As a C5ISR (command, control, communications, computers, combat systems, intelligence, surveillance, reconnaissance) aircraft, the F-35 is a networked platform that replaces those vulnerable support targets. A joint operation involving US, ROK, and JASDF F-35s is therefore more capable than the sum of its parts, which cannot yet be said for any PLAAF configuration.

For all the issues facing the Chinese aerospace forces in the East Asian security landscape, Xi Jinping has made their progress a special priority. At the 19th Party Congress in October, Xi mentioned both the PLAAF and the PLA Rocket Forces by name during his address, marking them as crucial to the development of a “world-class force.” One step toward the realization of that goal is the upcoming Xian H-20 stealth bomber, which would become the Chinese equivalent of the American B-2 and address concerns about the H-6K's capabilities. While the H-20 will effectively complete the Chinese nuclear triad, the advancements made in conventional strike capabilities by the PLARF are notable in their own right. A 2016 CSIS report highlights the development and proliferation of short- and medium-range conventional weapons as crucial to China's deterrence strategy. The PLARF was founded in 1966 as a branch of the Second Artillery Corps, to develop the deterrence capabilities of the Chinese nuclear arsenal. Its evolution from that role, to one of dual deterrence – nuclear and conventional – evinces a more diversified approach to regional security.

Xi's vision is borne out not in the hardware, but in the personnel. The new, more exclusive Central Military Commission includes former PLAAF commander Xu Qiliang as vice chairman and former PLARF commander Wei Fenghe in the third rank. While the PLAA has maintained dominance in the Central Military Comission (CMC), the aerospace forces have risen in prominence and will likely continue to do so as their respective capabilities improve. The takeaway from 2017 is that while current exercises reveal PLAAF limitations and underscore China's need for a regional alliance, progress has been made and will continue over the coming years.